I've been reading through some of the past postings and came across a few folks wondering what the mysterious EOS switch on certain devicesdo, like the ones found on some pop bumpers and score reels.
The End of Stroke switch on flippers are much different than what I'm discussing here. The flipper end of stroke switch is designed to reduce the current delivered to the flipper when its extended.
This will be old information for the experienced, but I put this together for the noob trying to save a pin.

So what does the End of Stroke switch do?
It works in conjunction with a relay to ensure a solenoid plunger positively reaches the end if its stroke. The EOS system is employed only on certain solenoids such as score reels and some pop bumpers.
It is important because if a pulse from the playfield switch is too brief the solenoid plunger will not reach its full travel. This error would cause score reels to miscount and pop bumpers (Where employed) to be weak.
EOS.gif

This animation can be confusing, but it really consists of 3 circuits:
1. The Pop Bumper Switch which activates the Pop Bumper Relay:
1-Relay-Circuit.jpg
2. The Pop Bumper Relay hold-in circuit:
2-Hold-In-Circuit.jpg
3. The Pop Bumper Solenoid circuit:
3-Solenoid_Circuit.jpg
If you examine the animation, you'll see:

1. The ball activates the switch for the pop bumper skirt. This switches on the relay.
2. The relay is held ON by its own switch, through the EOS switch.
3. The closed relay turns on the solenoid causing it to move.
4. The solenoid reaches the end of travel, and opens the EOS switch.
5. The open EOS switch causes the relay to drop off, which also opens the solenoid switch.
6. The plunger begins to travel back, and the EOS switch closes. Since the ball is no longer on the bumper skirt, the solenoid remains off and the plunger returns back to its rest position.

What can go wrong with the EOS system?
If the EOS switch opens prematurely (or simply open) the solenoid plunger won't always reach its full travel and the result is miscounted scores etc.
If something happens to prevent the EOS switch from opening, the solenoid and/or the associated relay can remain energized.
This can cause severe damage from burned out coils. What can cause the EOS not to open? There's always a mechanical bind in the solenoid or the mechanism it operates (ratchet or friction etc) or a maladjusted EOS switch.

Have anyone had an EOS circuit go bad? What lead you to the EOS circuit? What did you do to fix it? EOS circuit problems can be a lot easier to troubleshoot once you understand it.

I recently rebuilt a 1976 Williams. Occasionally the 10's digit would stop working occasionally on any of the 4 players. You'd hear the 10's relay "click" and hold on- and after a few moments, probably through vibration it would release and begin working again.
I double checked all the Playfield switches, score reel and 10's relay operation. Not the problem.
The problem was in the Player Unit.
The 10's relay would energize but the current couldn't pass through the Player Unit contacts so the score reel solenoid never pulled in to open the EOS switch.. so the relay would remain on.

I removed the rotating disk, cleaned all the contacts with #1000 sandpaper along with the contact shoes then gave it a light application of Teflon grease.

Thanks, I'm uploading a new one.

Thanks.
I see the animation is still kind of funky but... oh well.

For those who are just learning this, you'll usually find another set of switches on the relay which would operate a score reel relay (Which of course has its own EOS system). It's also important to know the wiring points may be different from machine to machine with slight variations to the circuit but the principal will be the same. Also, not all manufactures use an EOS system on their pop bumpers. My Williams pop bumpers for example use DC on their coils with no EOS circuit.

I'd love to add this to the PinWiki, with your permission, of course.

That will be fine Chris and if you wanted to include my score reels that's also ok.

I think GIF animations are great for small images with a few slides such as emoticons and advertisements and I knew I was pushing it to the limit with this project. Given that I set my expectations fairly low and I think it turned out so-so.
I think it's clunky and needs control buttons (not available on GIF) but it does show the sequence of events. In that, my goal was met. It was fun to do for a few hours.

I have another future project in mind.
The score reel reset sequence of a multi-player 1976 Gottlieb with its AX and Z relays in conjunction with the Player Unit would prove to be a very ambitious project. It might be cool to illustrate zeroing out 16 score reels chained together to reflect the US Federal debt:
Chain.jpg
This project would be well beyond the capability of MS paint and GIF so I'd need to build 3D models and sort out an understandable presentation like I did for a Pachinko machine:

Maybe I can start smaller and I'll use this same thread for future animations I may come up with.

I put together a few things last night that looks promising.

This is a collection of all the devices necessary to reset a 1976 gottlieb. A lot of cluttering circuits have been removed such as coin and credit handling, bonus unit etc to demonstrate the basic score reel reset.

It's a complicated reset procedure so I thought I'd start with the basics of score motor control (start/stop), move on to score reel zeroing out then how the Player Unit interacts with the Z relays. Once that's established it will be easy to show how the reels are chained together.

A good start anyway. The score motor cams are side to side instead of on top of each other for clarity.
Here's a screenshot- I haven't put all the switches in or any wires yet:

Setup.jpg

Thanks.
Pachinko.
These come from Japan, they can legaly be used there for a maximum of 2 years the become useless as their license can't be renewed. This means they are shipped around the world. Some people collect them like some people collect pinball.
The vast majority of ones you'll find on Craigs List are 1970's era of various condition which have been in storage for decades.
I didn't want to spend a lot of $ on them so I got ones that needed work. I paid $60 for one, $35 for another and a pair of late 1940's to 1950's machines, both for $100. It probably took 30 or so hours to restore each, and an additional ~$30 in materials.

My machines are fully restored, tested and clean which is not usually found on Craigslist. Given that, I would not expect to get more than $150 for one. People are insane when they post an "antique" rusted out piece of crap for a lot of money.

I personally place the pachiko machine only slightly higher on the "fun" meter as a slot or pachislo machine. I have them because people don't usually see them and become interested and want to flip a few balls.
I had the cable guy over a couple years ago, a japanese man who I had to practically pry him away from them.

If I wanted to compare "fun meters" between pinball and pachinko, well....
I play my pins everyday with few exceptions. The days skipped I simply don't have time. I like them a lot.
My pachinko's and slot machine will often sit for weeks without any play at all.

With that said, sometimes I just gotta flip a few balls for a few minutes. An irresistable urge. Gotta do it. Any longer than a few minutes and I get bored. Then they sit until next time.

I've seen some newer fully working pachinko models on CL for around $150 or so.
These have automatic shooters, and there's a sort of slot machine LCD screen in the center of the playfield. It's tempting but I'd never slip one past the Mrs. without severe consequences. :-\

I have a bit more done on this project.

The geometry is completed for score motor control, Start relay and Reset relay control. Next up is Player Unit and Z relay controls. The wires are a mess but I'll be able to isolate and break down each independent circuit, and pause the animation for each event:
Project-3.jpg

I had a bit of time tonight so I finished wiring this project. Here's a test render. Also, here's the individual circuits I'm using... for any circuit critic we may have...

Untitled-4.jpg Ckt_1_Score_Motor_Control.jpg Ckt_2_Start_Relay_Circuit.jpg Ckt_3_AX_Relay_Circuit.jpg Ckt_4_Z_Relay_Control.jpg Ckt_5_Score_Reel_Reset.jpg

Just a quick note.
I have the model all finished and running some test animations. Here's a really boring 16 second test run of the cycling score motor: